The present invention relates to improved micro mirrors and their method of fabrication.
A spatial light modulator (SLM) can be built with an array of tiltable mirror plates. Each mirror plate can be tilted by electrostatic forces to an “on” position and an “off” position. The electrostatic forces can be generated by electric potential differences between a planar electrode on the mirror plate and one or more opposing electrodes underneath the planar electrode on the mirror plate. In the “on” position, a reflective surface of the micro mirror plate can reflect incident light to form an image pixel in a display image. In the “off” position, the micro mirror plate directs incident light away from the display image. Despite the advances in the designs and fabrication of micro mirrors, relatively high voltages are usually required to produce enough electrostatic forces to produce appropriate tilt movements in the mirror plate. High voltages require high voltage drive electronic circuits that add complexity and cost to the devices. In addition, planar and stepped electrode mirror devices generate small electrostatic forces and suffer from adhesion problems when they operate in mechanical contact mode.